Method of making electrical contacts.



G. A. RIGNON.

METHOD OF MAKING ELECTRICAL coumrs.

- APPLlCATl0N FlLED SEl T- 30.1916- 1,264,685. Patented Apr. 30,1915;

METAL ATTORN EY UNITED STATES-PATENT OFFICE.

'G-IUSEPIPE ALBERTO RIG-NON-,' 0F GENOAgITALY Application filed September 30, 1916. Serial 1G0. 122,992.

To all whom it may concern.-

Be it known that I, GI'USEPPE ALBERTO RIGNON, a subjectof the King of Italy, residing at Genoa, Italy, have invented certain new and useful Improvements in ,the

Methods of Making Electrical Contacts, of

which the following is a specification.

This invention refers to improvements in the contacts of the contact breakers ofmagnetos employed for the ignition of the explosive mixture in internal combustion engines, and has for its object a new method of producing such contacts whereby all inconveniences which exist in those at present in.use are successfully eliminated. It is known in fact, that at present platinum is especially used for these contacts, but, in addition to its ever increasing price, it does not resist .very long the hammering produced by the interruption of the successive firing circuits and the heat produced by the spar s, and softens after a short time, thus increasing the distance between the contacts which causes irregular firing in the engine and serious wear in the. contact breaker itself.

According to this present invention the contacts are formed of tungsten or molybdenum or ofa metal of the iron group, of

an exceedingly high melting point, which are united with the support by electrothermical welding at a very high temperature, so as to render thewhole electrically homogeneous and therefore of minimum electric resistance, and said resistance is reduced by means of a coating of good conducting metal such as copper, or silver around the contact and the support, with the exception of the two faces between which the breaks take place.

Specification of Letters Patent.

METHOD OF IVlIAKING ELECTRICAL CONTACTS.

Patented pr. 30,1918.

Owing to the higher resistance to interruptions of the circuits presented by the contact as above formed, the two faces may be situated nearer one another than usual with the contacts used at present, thus obtaining perfect regularity and less wear of the parts.

The figure in the-accompanying sheet of drawing shows a form of the contact according to the present invention.

1 is the support for the contact, 3 the tungsten block and/2. a body of copper cast directly with the tungsten, 4 is the layer of good conducting metal whichv covers the I contact, with the exception of the face. 5

welding at a very high temperature, and

covering the support and the contact by coating them with good conducting metal such as copper or silver in order to reduce the resistance with theexception of the two faces between which the break takes place, substantially as described.

In testimony whereof I afi'ix my signature in presence of two witnesses.

' GIUSEPPE ALBERTO monon- Witnesses:

PIo NIMwrNG, I C. CLETUS'MHJLER. 

